Strongback



May 29, 1945.

A. [LPERTILE El A L STRONG BACK Filed M y 31,- 1945 /o, V7/l/ ///////////)'/'////I 'Fig.

Patented May 29, 1945 s'rRoNGBAo' ff Albeno D. Pertile and Henry'JQBarnett,"

Tacoma, Wash.

Application May 31, 1943, Serial No. 489,210

2 Claims.

This invention relates to means for temporarily bracing a pair of plates being welded and has for its primary object to save the great waste of material and time occasioned by the present practice of welding the strong-back to the plates to be welded, on each side of the weld. Further objects are to provide such a strong-back as may be quickly set up in place, or demounted therefrom; which, when thus set up, can apply the bracing pressure at any point between its ends; which provides means to keep said strong-back from twisting out of its set plane; and which is simple and cheap to make, easy to operate and effective in use.

We attain these and other objects as will readily appear to those familiar with the art of welding in ship building and similar industries, by the devices and arrangements illustrated in the accompanying drawing, in which Fig. 1 is a side elevation of our improved strongback in use; Fig. 2 is a perspective View thereof; and Fig. 3 is a view, partly in section, showing the end of one of the set screws used for holding the strong-back in place.

Similar numerals of reference refer to similar parts throughout the several views.

The particular condition under which we have illustrated the use of our improved strong-back shows it secured between a deck frame of a ship and a plate of one of the bulkheads thereof, and bracing the under sides of two deck plates, being welded together, but it is to be understood that this is for illustration purposes only as our strongback may be used under very many different conditions in ship building and other industrial uses.

The present practice is to form a strong-back by welding a plate to the under side of both of the plates being welded, said strong-back carrying a pair of bosses having set screws adapted to bring pressure under the two sides of the jointure of the two plates to be welded together. This practice is very expensive in materials as well as in the time of the workers required in its use, since the strong-back can only be used a comparatively few times and because of the time necessary to make the welds between the strongback and the under sides of the plates, as well as the time necessary to remove the strong-back from such welded position.

Referring, now, to the drawing it will be seen that our strong-back comprises a stiff compression plate I, of quite heavy steel or other suitable material, which is provided with two bosses on each side, the bosses 2 on the upper corners of the front side and the bosses 3 on the lower corners of the rear side. These bosses 2 and 3 have their axes horizontal and are provided with suitable screw-threaded holes 4. I

Suitable heavy set-screws 5 and. 6 are screwed, respectively, through the holes 4 in the several bosses 2 and 3, said set-screws projecting from the said bosses 2 and 3. The upper set-screws 5 are to be screwed outward into strong contact with the ship frame I and the bulkhead 8. The ends of these set-screws 5 are preferably slightly concaved in form, as seen at 9 in Fig. 3. The set-screws 5 are screwed tightly against the said parts I and 8 and their ends bite into the said parts so that the strong-back can withstand a considerable vertically downward force thereon without being moved. The purpose of the setscrews 6 is to reenforce the action of the set.

screws 5 and also to keep the strong-back from twisting out of the set plane when the vertical pressure applied thereto is not in the plane of the strong-back. This is especially necessary if the transverse plane of the deck plates l0, being welded, is not horizontal.

A sleeve ll envelopes the plate I and is slidable to any position thereon. This sleeve ll also carries, at the front side of the upper edge, a pair of bosses [2, having vertical axes provided with suitable screw-threaded holes l3 through which the heavy brace set-screws H are screwed upward to engage under the plates ID of the ship deck or other part to be welded together. The screws l4 are substantially in line with the clamping screws 5 and therefore do not cause any great twisting strain on the strong-back as set up in place.

Thus it will be seen that we have invented a strong-back which may be very quickly set up and applied to th ship structure; in which the pressure of the strong-back may be applied at any point between its ends; in which means is provided to prevent any twisting action out of the plane of action as set up; which may be quickly demounted; and which may be used an indefinite number of times with practically no Wear or deterioration.

It is, of course, to be understood that certain changes may be made in some of the details of our invention without departing from the spirit of our invention, as outlined in the appended claims.

Having, therefore, described our invention, what we claim, and desire to secure by Letters Patent, is: l

1. In a strong-back, the combination of a single stiff compression plate; screw-threaded bosses formed on the upper corners of said plate and having their axes horizontal; compression setscrews in said bosses and adapted to be screwed outward to firmly engage the supporting structure; a sliding sleeve mounted on said compression plate; a pair of screw-threaded bosses formed on the upper edge of said sleeveand having their axes vertical; and set-screws in said second bosses and adapted to be screwed upward to engage the under sides of the plates to be welded.

2. In a strong-back, the combination of a single stifi compression plate; screw-threaded bosses'on the upper corners of said plate and having their the plates to be welded; and means mounted on said compression plate and "engaging the supporting structure and adapted to prevent, the

, twisting of said strong-back out of its operative position.

ALBENO D. PERTILE. HENRY J, BARNETT. 

